001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.io;
020
021import java.io.*;
022
023import org.apache.hadoop.classification.InterfaceAudience;
024import org.apache.hadoop.classification.InterfaceStability;
025
026/** A WritableComparable for integer values stored in variable-length format.
027 * Such values take between one and five bytes.  Smaller values take fewer bytes.
028 * 
029 * @see org.apache.hadoop.io.WritableUtils#readVInt(DataInput)
030 */
031@InterfaceAudience.Public
032@InterfaceStability.Stable
033public class VIntWritable implements WritableComparable<VIntWritable> {
034  private int value;
035
036  public VIntWritable() {}
037
038  public VIntWritable(int value) { set(value); }
039
040  /** Set the value of this VIntWritable. */
041  public void set(int value) { this.value = value; }
042
043  /** Return the value of this VIntWritable. */
044  public int get() { return value; }
045
046  @Override
047  public void readFields(DataInput in) throws IOException {
048    value = WritableUtils.readVInt(in);
049  }
050
051  @Override
052  public void write(DataOutput out) throws IOException {
053    WritableUtils.writeVInt(out, value);
054  }
055
056  /** Returns true iff <code>o</code> is a VIntWritable with the same value. */
057  @Override
058  public boolean equals(Object o) {
059    if (!(o instanceof VIntWritable))
060      return false;
061    VIntWritable other = (VIntWritable)o;
062    return this.value == other.value;
063  }
064
065  @Override
066  public int hashCode() {
067    return value;
068  }
069
070  /** Compares two VIntWritables. */
071  @Override
072  public int compareTo(VIntWritable o) {
073    int thisValue = this.value;
074    int thatValue = o.value;
075    return (thisValue < thatValue ? -1 : (thisValue == thatValue ? 0 : 1));
076  }
077  
078  @Override
079  public String toString() {
080    return Integer.toString(value);
081  }
082
083}
084